Volcano: A place where the crust is weak, and there is magma on the surface. Magma: Molten rock combined with rock substances from gases in the mantle. Lava: Places where the magma reaches Earth's crust. Island Arc: The places when volcanoes create a line of islands. Hot Spot: An area where magma (form the mantle) melts through the crust. Ring of Fire: One serious volcanic belt.
Outline
What is a Volcano?
Volcano eruptions- very dangerous
Cooled lava can form islands
Location of Volcanoes
About 600 active volcanoes on land
Most occur on diverging plate boundaries/hot sptos
Volcanoes occur in Belts
Major belt- Ring of Fire
Forms along boundaries
Volcanoes at Diverging Plate Boundaries
Form along mid- ocean ridge- volcanoes
some places mid-ocean ridge extends above surface
Volcanoes at Converging Plate Boundaries
When subduction happens at ocean floor, crust falls and rises as magma
Oceanic crust falls into asthenosphere and turns hot and melts to form magma
This is because surrounding rock is denser, magma seeps upward through cracks
Finally it breaks though ocean floor, creating volcanoes
These volcanoes make island arcs (see definition)
Hot Spot Volcanoes
A hot spot is when magma is very large/dense (like a blow torch)
Table of Contents
3.1 Volcanoes and Plate Tectonics (pg. 78)
Vocabulary
Volcano: A place where the crust is weak, and there is magma on the surface.
Magma: Molten rock combined with rock substances from gases in the mantle.
Lava: Places where the magma reaches Earth's crust.
Island Arc: The places when volcanoes create a line of islands.
Hot Spot: An area where magma (form the mantle) melts through the crust.
Ring of Fire: One serious volcanic belt.
Outline
What is a Volcano?
Location of Volcanoes
Volcanoes at Diverging Plate Boundaries
Volcanoes at Converging Plate Boundaries
Hot Spot Volcanoes
- A hot spot is when magma is very large/dense (like a blow torch)
- Hot spots create lots of volcanoes
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